The Overlooked Effects of Atmospheric Carbon Dioxide, and How They Should Inform Environmental Policy

October 10, 2019 by Bryce Brenda

By Wyatt Kayne, Staff Contributor.

Scientists frequently warn carbon dioxide is a primary culprit of rising global temperatures and its associated problems. Nevertheless, studies suggest fixating on reducing carbon dioxide emissions may not be the most effective, efficient, or worthwhile way to combat climate change.

One of the most commonly cited environmental challenges facing humanity is rising carbon dioxide levels in the atmosphere.[1] Scientists repeatedly warn that this greenhouse gas is the primary culprit of rising global temperatures, which has caused melting polar ice caps, elevated sea levels, vanishing coastal regions, and a mass migration crisis.[2] While these harms should be taken into account in the cost-benefit analysis of environmental policy, such analysis often fails to consider the significant benefits of increased carbon dioxide levels. In particular, elevated carbon dioxide levels can be highly beneficial to plant growth.[3] Studies suggest that increased carbon dioxide emissions have caused a boom in global crop production, which has contributed enormously to the global economy and helped reduce worldwide starvation.[4] Research also suggests elevated carbon dioxide levels have helped mitigate the problems of deforestation.[5] Furthermore, carbon dioxide is colorless, odorless, non-toxic, and may not be as large a driver of increased climate temperatures as many believe it is.[6] Such findings suggest modern environmental policy may be better served by focusing on reducing the emission of toxic chemicals—which can often be achieved through advanced filtration and improved combustion technology—and should be less concerned with limiting overall carbon dioxide emissions levels.

Increased atmospheric carbon dioxide levels have significant positive externalities (though, to be clear, the increase is not necessarily beneficial overall). A recent study by the Center for the Study of Carbon Dioxide and Global Change suggests staggering benefits have resulted from increased carbon dioxide emissions: “[T]he annual total monetary value of this benefit grew from $18.5 billion in 1961 to over $140 billion by 2011, amounting to a total sum of $3.2 trillion over the 50-year period 1961-2011. Projecting the monetary value of this positive externality forward in time reveals it will likely bestow an additional $9.8 trillion on crop production between now and 2050.”[7] These enormous benefits to humanity must not be overlooked and must be weighed against the costs of elevated carbon dioxide levels, especially when evaluating policy that would barely pass a cost-benefit analysis test in absence of such benefits.

Research also suggests increased carbon dioxide emissions may not be as significant a contributor to rising climate temperatures as many believe—atmospheric water vapor instead is by far the most significant source of the greenhouse effect.[8] Such studies undermine the view that major reductions in carbon dioxide emissions are critical to limiting rising climate temperatures. Moreover, these studies are buttressed by the work of climate scientists such as Judith Curry, whose findings suggest there are large uncertainties involved in estimating the impact of carbon dioxide emissions on global temperatures and that studies consistently underestimate the role of natural forces in changing temperatures.[9] All of this is to conclude that environmental policy analysis would be well-served to take into account evidence that fixating on reducing carbon dioxide emissions may not be the most effective, efficient, or worthwhile way to combat climate change.

[1] Susan Solomon et al, Irreversible climate change due to carbon dioxide emissions, Proc. of the Nat’l Acad. of Sciences, 1704-1709 (2009).

[2] Id.

[3] Matt Ridley, Global Warming Versus Global Greening, The Global Warming Policy Foundation, 2 (October 17, 2016),

[4] The Effects of Climate Change, NASA (October 9, 2019),

[5] Id.

[6] Judith Curry Retires, E&E News (January 4, 2017),

[7] Craig D. Idso, The Positive Externalities of Carbon Dioxide: Estimating the Monetary Benefits of Rising Atmospheric CO2 Concentrations on Global Food Production, Center for the Study of Carbon Dioxide and Global Change, 2 (October 21, 2013),

[8] A Primer on Carbon Dioxide and Climate, CO2 Coalition, 2 (February 22, 2016),

[9] Judith Curry Retires, E&E News (January 4, 2017),